Multiple bypass port phaco tip

ABSTRACT

Phaco tip apparatus for a phacoemulsification/irrigation and aspiration handpiece having a drive assembly including a needle having a tip for emulsifying a cataractic lens and a lumen communication with primary and a secondary aspiration ports for aspirating emulsified lens. A sleeve establishes an annular passage around the needle and enables irrigation fluid to pass into an eye through a cornea/sclera wound while cooling the needle. A bypass port, disposed in said needle and under said compressible sleeve, establishes fluid communication between the lumen and the annular passage in order to enable irrigation fluid to pass into said lumen upon clogging of the primary and secondary aspiration ports, thus providing fluid surge protection. A depending member may be disposed within said compressible sleeve limits compression of opposing walls of said compressible sleeve in order to prevent contact of said compressible sleeve with the needle, maintain the annular passage flow of irrigation fluid past the needle and prevent the compressible sleeve from closing the bypass port.

The present application is a continuation-in-part of U.S. Ser. No.09/675,339 filed Sep. 28, 2000, which is a continuation-in-part of U.S.Ser. No. 09/163,985 filed Sep. 30, 1998, now U.S. Pat. No. 6,033,376.

The present invention generally relates to phacoemulsificationhandpieces for the removal of a cataract lens from an eye and is moreparticularly related to phaco tip apparatus for a phacoemulsificationhandpiece. A well known method for the removal of a cataract through asurgical incision in the eye is known as phacoemulsification. Ahandpiece for phacoemulsification generally includes an ultrasonic orsonic generator which is attached to a hollow needle which is vibratedand, when inserted into an eye, is capable of emulsifying an eye lensand aspiration thereof through a lumen in the needle. The needle issurrounded by a sleeve when inserted through an incision in the eye. Thetip of the needle engages and emulsifies the cataract and a suctionforce is applied through the needle interior lumen to withdraw theemulsified cataract into the needle and out of the eye.

The sleeve protects the wound through which the needle is passed fromcontacting the needle which can become heated, and the sleeve furtherestablishes an annular passage around the needle for providing anirrigation fluid to the eye, while at the same time cooling the needle.

Typically, the cornea or sclera incision is linear and has a lengthapproximately to one-half the circumference of the sleeve in order tominimize fluid leakage from the incision, or wound, when theneedle/sleeve is inserted therethrough.

A great number of sleeve designs have been proposed and a number ofmaterials have been utilized in prior art sleeves. For example, U.S.Pat. No. 4,787,889 to Steppe et al, discloses a flexible sleeve made ofa synthetic resin such as silicon rubber which is able to fold back ortelescope when inserted through an incision. The problems with theseprior art devices include collapsing of the flexible sleeve in the areaof the wound by pressure from surrounding tissue. This collapsing of thesleeve blocks flow of the irrigation to the surgical site and around thevibrating needle, which can cause overheating and damage to adjacenttissue. Sleeves made out of metallic material, such as also described inthe hereinabove referenced U.S. patent, do not allow collapse and,accordingly, allow a greater amount of fluid leakage from the wound.

In order to minimize leakage from the wound past the sleeve, anelliptical sleeve has been proposed, for example, see U.S. Pat. No.5,084,009. This collapsible, or compressible, sleeve is made with ashape matching the configuration of a surgical incision in order tominimize leakage between the exterior surface of the sleeve and thesurgical incision. However, in order for the ultrasonic needle toexhibit a desired and vibratory motion, which is relatively free fromdamping, this elliptical sleeve must be prohibited from touching theneedle during the operation.

During phacoemulsification procedures, the needle must be partiallyrotated and its angle of incident changed in order to effect completephacoemulsification and removal of the lens. In these procedures, a softsleeve, particularly one shaped to the size of the wound, may collapse,or deflect against the ultrasonic needle. When the sleeve is pushedagainst the rapidly vibrating needle, the needle and sleeve tend tooverheat due to friction, which may damage delicate cornea or scleratissue, particularly the corneal epithelium.

Also during phacoemulsification procedures, an emulsified lens particlemay block the aspirating lumen. The blockage may be sufficient torequire reversal of fluid flow through the lumen in order to dislodgethe blockage. This interruption may cause undesirable pressure changesin the eye. Many equipment designs and methods have been derived inorder to minimize the problems introduced by a blocked aspiration lumen.Among such designs is the use of a bypass port between the irrigationfluid in the sleeve and the aspiration lumen of the needle. Such a portenables irrigation fluid to be aspirated when the primary port isoccluded to prevent surge to the eye.

Unfortunately, when such a bypass port is used in conjunction with acompressible sleeve, inadvertent closure of the port may occur.

The present invention is directed to a sleeve which shapes itself to thewound by pressure of surrounding tissue in order to minimize leakage offluid therepast. In addition, internal structure of the sleeve maintainsproper annular channel around the needle for passage of cooling fluid.Accordingly, the needle is prevented from touching the sleeve. Inaddition, the sleeve is attached to the phacoemulsification handpiece toenable angular motion of the needle within the sleeve so that the sleevewound junction is not disturbed. Further structure is provided toprevent any closure of a bypass port as hereinabove noted.

In one embodiment of the present invention, multiple ports are providedwith one of the ports outside the sleeve and another under the sleeve asherein above noted.

SUMMARY OF THE INVENTION

Phaco tip apparatus in accordance with the present invention is suitablefor a phacoemulsification handpiece having an ultrasonic drive assemblyfor emulsifying and aspirating a cataract lens through a cornea/sclerawound.

The subject phaco tip apparatus generally includes a needle having atip, for emulsifying a cataract lens through a cornea/sclera wound, andlumen through the tip to provide a primary aspiration port foraspirating emulsified lens. A sleeve provides a means for establishingan annular passage around the needle and enabling the irrigation fluidto pass into an eye through the cornea/sclera wound while simultaneouslycooling the needle. The sleeve may be compressible as hereinafterdescribed.

A bypass port is disposed in the needle and beneath the compressiblesleeve for establishing fluid communication between the lumen and theannular passage in order to enable irrigation fluid to pass into theneedle lumen upon clogging, or blocking of the primary port of the tip.Thus, the bypass port protects, or lessens, any surge of fluid and/orfluid negative pressure in the eye when the primary port is unblocked.

In addition, a secondary aspiration port may be provided and disposed inthe needle between the needle end and the sleeve for enabling continuedaspiration of fluid upon clogging of the primary aspiration port.

The sleeve when compressible, preferably includes a wall configurationwhich provides a means for controlling compression of the sleeve inorder to cause the compressible sleeve to shape and conform to thecornea/sclera wound and limit fluid egress from the wound. That is, theconstruction of the compressible sleeve wall enable the sleeve, uponcompression by tissue subtending the wound, to fill, or contact, all ofthe wound surface so that no gaps are established which can permit theleakage of fluid.

In addition, a hub means may be provided for attaching the compressiblesleeve to the handpiece and for enabling the needle to be angularlydisplaced within the compressible sleeve means. Thus, once thecompressible sleeve is conformed to the wound shape, it need not bedisturbed by subsequent manipulation of the needle which is necessary inorder to properly emulsify and aspirate a cataract lens.

In one embodiment of the invention, the compressible sleeve includes avariation in wall thickness around the circumference of the compressiblesleeve which may include two areas of the sleeve wall having greaterthickness than adjoining areas in the sleeve wall. These two areas arepreferably spaced apart from one other at about 180° around the sleevemeans circumference. Thus, when the compressible sleeve is inserted intoa slit type cornea/sclera wound, the thicker portions of the wall aredisposed at opposite ends of the slit and compression of the sleeveenables confirmation of the sleeve with all of the surrounding woundtissue including the ends of the slit.

Still more particularly, the two areas of greater wall thickness mayinclude nodules which extend outward from the compressible sleeve means.

In another embodiment of the present invention, the sleeve may include avariation in wall density of the sleeve walls around the circumferenceof the sleeve. The variation in wall density preferably includes twoareas of the sleeve having a lower density than adjoining areas of thesleeve wall, with the two areas of lower density being spaced apart fromone another at 180° around the sleeve means configuration.

In a manner as similarly described in conjunction with a wall havingthicker areas, this lower density area enables a preferentialcompression of the sleeve and outward extension of the sleeve in a lowdensity wall areas so that the sleeve can conform and contact with allof the tissue surrounding the slit wound.

Also, in accordance with the present invention, in order to limitcompression of opposing walls of the compressive sleeve to preventcontact of the compressible sleeve with the needle, and undesiredclosure of the bypass port at least one depending member is provided. Inaddition to prevention contact of the compressible sleeve with theneedle, and closure of the bypass port by the compressive sleeve,continued cooling of the needle is ensured at all times.

More particularly, two depending members having a length greater thanthe diameter of the needle, may be disposed within the compressiblesleeve and are attached to opposing walls between the two wall areas ofgreater thickness, or lesser density.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be more clearly appreciated when taken inconjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a phacoemulsification handpiece usingthe phaco tip apparatus in accordance with the present invention as itmay be inserted through a cornea/sclera wound for the removal of acataract lens from a lens capsule;

FIG. 2 is a cross-sectional view of the phaco tip apparatus inaccordance with the present invention including a needle with a lumenaspiration of emulsified lens through a primary aspiration port, asecondary aspiration port along with a bypass port therein, acompressible sleeve and a hub for attaching the sleeve and needle to thephacoemulsification handpiece;

FIG. 3 is a cross-sectional view of a prior art sleeve as inserted intoa slit type wound illustrating the problem with regard to gaps beingcreated by such insertion which provide a means for fluid egress fromthe eye during the phacoemulsification procedure;

FIG. 4 is a cross-sectional view of one embodiment of the presentinvention showing a compressible sleeve having side wall of greaterthickness disposed in an opposing relationship around the compressiblesleeve along with a pair of depending members which are provided forlimiting the collapse of the collapsible sleeve and along with a pair ofdepending members which are provided for limiting the collapse of thecollapsible sleeve and preventing closure of the bypass port;

FIG. 5 is the collapsible sleeve as shown in FIG. 4 shown inserted intoa slit type cornea/sclera wound, with the outside, or perimeter, of thecollapsible sleeve conforming exactly to the slit opening uponcompression of the sleeve so that little or no gaps are established forthe egress of fluid;

FIG. 6 is an alternative embodiment of the present invention in whichside walls include a lower density in opposing walls for enablingpreferential collapse of the collapsible sleeve and a bypass portdisposed in the needle adjacent the dependant member; and

FIG. 7 shows the sleeve as shown in FIG. 6 as it conforms to a slitcornea/sclera wound.

DETAILED DESCRIPTION

With reference to FIG. 1, there is shown a phacoemulsification handpiece10 utilizing sleeve apparatus 12 in accordance with the presentinvention for removing a cataract lens 16 by emulsification/aspirationthrough a cornea/sclera wound 20. The phaco handpiece, or instrument 10,may be of any conventional type operating, as is well known to thoseskilled in the art, except as modified with the phaco tip apparatus 12in accordance with the present invention.

As more clearly shown in FIG. 2, the sleeve apparatus 12 in accordancewith the present invention includes a sleeve 26 and a hub 28 fixedthereto. It should be appreciated that the sleeve 26 and hub 28 may beformed from the same type of material, for example, a silicone orsilicone-type material or of a thermoplastic polyurethane and that thesleeve 26 and the hub 28 may be either fixed to one another or formedintegrally.

The handpiece 10 includes a sonic or ultrasonic drive assembly, notshown, attached to a hollow needle 32, which includes a primaryaspiration port 34 in an end 36 of the needle 32 and at least onesecondary port aspiration 38 disposed proximate the end 36 of the needle32. The end 36, including the secondary aspiration port, protrudesthrough the sleeve 26 at a sleeve distal end 40 with a flexible seal 42disposed there between.

The secondary aspiration port 38, being disposed outside the sleeve 26between the needle end 34 of sleeve enables continued aspiration ofemulsified lens upon clogging of the primary aspiration port.

As shown, an annular passage 44 is established between an inside surface46 of the sleeve 26 and an outside surface 47 of the needle 32 in orderto enable irrigation fluid provided by the handpiece 10 to pass aroundthe needle 32 and past the flexible seal 42 or a port 48 in aconventional manner as represented by the arrows 49-50 respectively. Thefluid interconnection between the annular passage 44 and the handpieceis not shown, as this arrangement is well known in the area.

A bypass port 51 in the needle under the sleeve 26 establishes fluidcommunication between the needle lumen 52 and the annular passage 44 inorder to enable irrigation fluid to pass into the lumen 52, as indicatedby an arrow 54, upon partial clogging of the primary aspiration port 34or total clogging of the primary and secondary aspiration ports 34, 38.Thus, providing fluid surge protection. There may be a small amount offluid transferred between the annular passage 44 and lumen 52 duringnormal, unblocked aspiration, but this fluid flow is not important inthe overall operation of the phaco tip 12.

It has been found that for a needle diameter of 1.1 mm with a lumenhaving a cross-sectional area of the secondary aspiration port 38 shouldbe between about 5% and about 15% of the cross-sectional area of thelumen 52. The cross-sectional area of the bypass port 50 should bebetween about 5% and about 15% of the cross-sectional area of the line52.

It is important, during a phacoemulsification procedure, that tissuesurrounding the cornea/sclera wound 20 not be damaged, particularly theepithelium layer under the cornea. Since damage to this tissue may occurdue to heating, a prior art sleeve 56, see FIG. 3, has been typicallyprovided with sufficient resiliency in order to prevent total collapseof the sleeve 56 in order to maintain a fluid conduit 58 between thesleeve 56 and the needle 32. While aspiration of cataractic tissue, notshown, is performed through a needle lumen 60, sufficient cooling isonly provided by the irrigation of fluid passing through the passage 58.It must also be appreciated that this size of the needle 32 and sleeve58 is quite small, since the length of the slit cornea/sclera wound maybe only about 3 mm.

Not only is it important that the passage 58 be maintained for coolingof the needle, it is also important that the needle 32 does not contactthe sleeve 56 because conductive heat transfer to the tissue surroundingthe wound 20 would cause undesired heating. Also, a collapsed sleeve 26may cause closure of the bypass port 50 which would defeat its intendedoperation.

The rigidity or relative rigidity of the prior art sleeve 56, as isnecessitated by the constraints hereinabove set forth, preclude thesleeve 56 from shaping, or conforming, to the slit wound 20. Rather,gaps 64 between the sleeve 56 and the wound 20 occur which enableleakage of irrigation fluid therepast. This leakage is undesirable, asis well known in the art, because it interferes with proper maintenanceof ocular pressure during the phacoemulsification procedure.

As shown in FIGS. 4 and 5, the sleeve 26 in accordance with the presentinvention, overcomes the deficiencies of the prior art sleeve 56, byincorporating a sleeve wall which provides a means for controllingcompression of the sleeve 26 in order to cause the compressible sleeve26 to shape and conform to the cornea/sclera wound 20, thus limitingfluid egress from the wound, see FIG. 5.

Referring again to FIG. 4, a variation in sleeve wall 68 thickness isprovided in two areas, 72, 74 around the sleeve 26 and preferably spacedapart from one another at a 180° angle in order to enable the sleeve 26to shape and conform to the cornea/sclera wound 20 as shown in FIG. 5.

Because the areas 72, 74 are thicker than adjacent areas 76, 78, 80, 82,respectively, controlled collapse of the sleeve 26 under pressure ofsurrounding tissue, not shown in FIG. 4, is provided. In order tofurther enhance sealing between the sleeve 26 and the wound 20, thethicker areas may be in the form of nodules 72, 74. In this manner, thesleeve 26 completely shapes, or conforms, to the wound 20 as shown inFIG. 5.

In order to prevent the compression, or collapse of the sleeve onto theneedle 32 and closure of the bypass port 50, depending members 88, 90are provided. With a length greater than a diameter of the needle 32,the depending members 88, 90 prevent contact of the sleeve 26 with theneedle 32 maintain an annular passage 94 therebetween, see FIG. 5.

The depending members 88, 90 may be formed of the same material as thesleeve and integrally formed thereto. It should also be appreciated thatthe members 88, 90 need only be present on an inside of a surface 96 ofthe sleeve 26 in an area 100 of the sleeve passing through the wound 20,see FIG. 1.

The depending members 88, 90 may be attached to opposing walls 102, 104of the sleeve 26 which will result in the same compressed configurationas shown in FIG. 5.

Because of the important conformation of the sleeve 26 with the wound20, rotation of the sleeve within the wound 20 is not desirable.Accordingly, in order to enable the needle 32 to be angularly displacedwithin the compressible sleeve 26, the hub includes snap fittings 108which enable rotation of the hub 28 and sleeve 26. Thus, the sleeve 26may be held in an orientation affording proper shaping of the sleeve 26with the wound 20, while the needle is angularly moved within the sleeveand further axially tilted within the wound 20 in order to effect aproper emulsification of the lens 16 and aspiration thereof through theneedle lumen 60.

As hereinabove discussed, it is important that the sleeve 26 includeswall means 68 for controlling compression of the sleeve 26 and in thatregard, and alternate wall means 114 may be provided for an alternatesleeve 116 as shown in FIG. 6. In this embodiment, the wall 114 includesareas of a lower density 120, 122 surrounded by areas 124, 126, 128, 130of heavier density which enables collapse of the sleeve upon compressionby surrounding wound tissue so that the sleeve 116 takes the shape andconforms to the wound 20 as shown in FIG. 7. Hence, the many gaps, notshown, are not established between the sleeve 116 and the wound 20 inorder to prevent undesirable egress of irrigation fluid as hereinabovediscussed. Dependent members 88, 90 are also provided within the sleeve116 and function in a manner identical to the members 88, 90, shown inFIGS. 4 and 5.

Although there has been hereinabove described specific embodiments ofphaco tip apparatus, in accordance with the present invention, for thepurpose of illustrating the manner in which the invention may be used toadvantage, it should be appreciated that the invention is not limitedthereto. Accordingly, any and all embodiments, variations, or equivalentarrangements which may occur to those skilled in the art, should beconsidered to be within the scope of the present invention as defined inthe appended claims.

What is claimed is:
 1. A phaco tip apparatus for a phacoemulsificationhandpiece having vibration drive assembly, said phaco tip apparatuscomprising: a needle having a tip for emulsifying a cataract lensthrough a cornea/sclera wound; a lumen through the tip and providing aprimary aspiration port to the needle for the aspiration of emulsifiedlens; a sleeve for establishing an annular passage around the needle andenabling irrigation fluid to pass into an eye through the cornea/sclerawound while cooling the needle, said sleeve having a length shorter thana length of the needle; a secondary aspiration port disposed in saidneedle between the needle end and the sleeve for enabling continuedaspiration of emulsified lens upon clogging of the primary aspirationport; and a bypass port, disposed in said needle and under saidcompressible sleeve, for establishing fluid communication between saidlumen and said annular passage in order to enable irrigation fluid topass into said lumen upon clogging of the primary and secondaryaspiration ports.
 2. The phaco tip apparatus according to claim 1wherein said sleeve is compressible.
 3. The phaco tip apparatusaccording to claim 1 wherein a cross-sectional area of said secondaryaspiration port is between about 5% and about 15% of the cross-sectionalarea of said lumen.
 4. The phaco tip apparatus according to claim 3wherein a cross-sectional area of said bypass port is between about 5%and about 15% of the cross-sectional area of said lumen.
 5. The phacotip apparatus according to claim 4 where the secondary aspiration portcross-sectional area is between 5% and 15% of the bypass portcross-sectional area.
 6. Phaco tip apparatus for a phacoemulsificationhandpiece having vibration drive assembly, said phaco tip apparatuscomprising: a needle having a tip for emulsifying a cataract lensthrough a cornea/sclera wound; a lumen through the tip and providing aprimary aspiration port in an end of the needle for the aspiration ofemulsified lens; a compressible sleeve for establishing an annularpassage around the needle and enabling irrigation fluid to pass into aneye through the cornea/sclera wound while cooling the needle, saidcompressible sleeve having a length shorter than a length of the needle;a secondary aspiration port disposed in said needle between the needleend and the sleeve for enabling continued aspiration of emulsified lensupon clogging of the primary aspiration port; a bypass port, disposed insaid needle and under said compressible sleeve, for establishing fluidcommunication between said lumen and said annular passage in order toenable irrigation fluid to pass into said lumen upon clogging of theprimary and secondary aspiration ports; and a depending member disposedwithin said compressible sleeve for limiting compression of opposingwalls of said compressible sleeve in order to prevent contact of saidcompressible sleeve with said needle, maintain the annular passage flowof irrigation fluid past said needle and prevent the compressible sleevefrom closing said bypass port.
 7. The phaco tip apparatus according toclaim 6 wherein a cross-sectional area of said secondary aspiration portis between about 5% and about 15% of the cross-sectional area of saidlumen.
 8. The phaco tip apparatus according to claim 7 wherein across-sectional area of said bypass port is between about 5% and about15% of the cross-sectional area of said lumen.
 9. The phaco tipapparatus according to claim 8 wherein the secondary aspiration portcross-section is between about 5% and 15% of the bypass portcross-section.